Just choose the answer.

f ( x , v ) = sin 1 ( x 2 + y2) Domain: all points in the xy-plane satisfying x2 + y2 s 1; range: real numbers - - s z s ; level curves: circles with centers at (0, 0) Domain: all points in the xy-plane; range: real numbers - - s z s - ; level curves: circles with centers at (0, 0) Domain: all points in the xy-plane satisfying x2 + y2 s 1; range: real numbers - _ s z s ; level curves: circles with centers at (0,0) and radii r, O